<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    #app{
        width: 100px;
        height: 100px;
        border: 1px solid orangered;
    }
</style>
<body>
    <div id="app" draggable="true">
        可拖拽
    </div>
    <script>
        // 单位时间以内只触发一次，
        // 鼠标移动距离测算
        // input  http 搜索
        
        // 节流：无论你拖拽一个元素多快，时间都会每隔500ms触发一次
        // 节流可以让函数变得平滑
        let timer = null;
        const app = document.getElementById("app");
        app.addEventListener("drag",function(e){
            if(timer){
                return 
            }
            timer = setTimeout(()=>{
                console.log(e.offsetX,e.offsetY);
                timer = null;
            },500)
        })
    </script>
</body>
</html>